Rises in obesity prevalence over recent decades have corresponded with increasing stigmatisation of, and discrimination against, individuals living with obesity. Weight stigma is often justified on the basis that it might encourage people to lose weight, but a growing evidence base indicates that experiences of weight-related stigmatisation may in fact encourage behaviours that promote obesity.

A few small studies have indicated that people who face weight stigma are more inclined to avoid physical activity, but none have been able to clearly establish what effect experiencing stigma has on actual exercise behaviour.

In a new study published today in BMJ Open we explored the relationship between weight discrimination and physical activity. The research involved 5,480 men and women aged 50 years and older taking part in the English Longitudinal Study of Ageing, a large population-based cohort of middle-aged and older adults living in England.

Overall, one in twenty people said they had been discriminated against because of their weight, ranging from lack of respect or courtesy to being threatened or harassed. Rates of weight discrimination varied considerably according to how overweight a person was, from 0.9% of people with a body mass index (BMI) in the overweight range (25-29.9) to 13.4% of people with obesity (BMI greater than 30).

Importantly, we found that people who had experienced weight-related discrimination had almost 60% higher odds of being inactive and 30% lower odds of engaging in moderate or vigorous exercise once a week than their peers.

Interestingly, a person’s BMI in itself did not affect the relationship between weight discrimination and exercise, indicating that people who experience weight-related discrimination are likely to be less physically active, regardless of their weight.

There could be several reasons for our findings. People who feel stigmatised may be more self-conscious about exercising in front of others for fear they will attract undesirable attention, leading to embarrassment or teasing. They may also begin to believe the negative stereotypes against themselves as lazy and worthless, leaving them wondering why they should bother trying to be active.

Given the substantial benefits of being physically active for both physical and mental health, interventions that aim to reduce weight bias at a population level – for example through schools, local communities or national campaigns – may have greater impact on health than those that encourage people to lose weight. A Health at Every Size approach may be helpful in encouraging people to develop and maintain healthy habits, including regular physical activity, for the sake of health and wellbeing as opposed to weight control.

Stigmatisation of obesity remains one of “the last acceptable forms of prejudice”. People with obesity are widely stereotyped as lazy, weak willed and personally to blame for their weight by the media, employers, educators, health care professionals, and even their friends and family.

Facing discrimination can understandably be very stressful in the moment. Smallexperiments have shown that asking people to watch a video that stigmatises obesity, or telling them that their body size and shape are unsuitable to take part in a group activity, increases levels of the stress hormone cortisol in their saliva.

But what wasn’t known until now was whether discrimination has lasting effects on stress levels. This is important because acute (short-term) stress is a protective, adaptive response whereas chronic stress can have a damaging effect on the body.

In a new study published last week in Obesity we explored the relationship between weight discrimination and chronic stress. The research involved 563 men and women with obesity (body mass index ≥30) aged 50 years and older taking part in the English Longitudinal Study of Ageing (ELSA), a large population-based cohort of middle-aged and older adults living in England.

Rather than measuring levels of cortisol in saliva, which are sensitive to daily fluctuations and short-term factors such as diet, we analysed cortisol levels in hair. Measuring hair cortisol is a new technique that gives an indication of average levels of cortisol in the body over several months. Hair grows at approximately 1 cm per month, so the 1 cm of hair nearest to the scalp represents average exposure to cortisol over the last month.

We found that one in eight people with obesity had experienced discrimination because of their weight, ranging from lack of respect or courtesy to being threatened or harassed. Among people with severe obesity (BMI ≥40), one in three reported discrimination.

Importantly, our findings revealed that average levels of cortisol in hair were 33% higher in individuals who had experienced weight discrimination than those who had not. People who experienced more frequent weight discrimination had higher hair cortisol levels than those who faced less regular discrimination.

The results of this study provide evidence that weight discrimination is associated with the experience of stress at a biological level. Because experiencing high levels of cortisol over a prolonged period can have a substantial impact on health and wellbeing, it is likely that weight discrimination contributes to many of the negative psychological and biological consequences of obesity. In addition, cortisol is known to increase appetite and fat storage, making people who experience weight discrimination more likely to gain weight.

Cancer survivorship rates are improving dramatically, with half of all people diagnosed with cancer in the UK now expected to survive for at least ten years. Although treatment of the cancer is the primary clinical goal, ensuring the best possible quality of life after treatment is important. Preservation of sexual function is a key component of quality of life, yet remains a commonly reported ‘unmet need’ by cancer survivors. However, sexual function declines with ageing and because the majority of cancers are diagnosed in the over-70s, it was previously unclear whether changes in sexual wellbeing reported by cancer survivors are a result of their disease or a natural by-product of ageing.

In a new study published today in Cancer we explored differences in sexual activity, function and concerns between cancer survivors and people who had never received a cancer diagnosis. The findings revealed that a diagnosis of cancer does not seem to affect whether or not people have sex, how often they have sex, what they do when they have sex, and (in the case of men) their sexual function. Compared with women of a similar age, women who had been diagnosed with cancer within the past five years were just as likely to be sexually active, although they were more likely to report problems with arousal. Following the five years post-diagnosis the only difference was greater dissatisfaction with their sex lives, with 18% of women with a history of cancer reporting dissatisfaction compared to 12% of cancer-free women. Male cancer survivors did not report any more sexual problems than their age-matched counterparts, but they were more dissatisfied with their sex lives (31% of men with cancer compared to 20% of men with no history of cancer).

The research involved 2982 men and 3708 women aged 50 years and older taking part in the English Longitudinal Study of Ageing (ELSA), a large population-based cohort of middle-aged and older adults living in England. Participants reported whether they had ever been diagnosed with cancer, and completed the Sexual Relationships and Activities Questionnaire, a comprehensive measure that includes questions on the frequency of sexual behaviours, problems with sexual activities and function, and concerns and worries about sexual activities, function and relationships. It is the first study to compare sexual behaviour and concerns between cancer survivors and controls from the same population-based study using a standardised measure.

The results of this study are generally encouraging in showing that older people with cancer do not experience greater problems with sexual activity or functioning than people of the same age without a history of cancer. However, with more than one in five men and one in nine women reporting that they were dissatisfied with their sex lives, it is clear that there is a need to identify interventions to enhance sexual health in ageing men and women. In the meantime, better advice on the normal changes in sexual activity and functioning that occur with ageing could help to address the mismatch between the normal sexual behaviour and lower sexual satisfaction seen in cancer survivors.